An integrative strategy for comprehensive determination of nineteen constituents from Eupatorii Herba and application in pharmacokinetic study by combing UHPLC-QTRAP-MS/MS with gC-MS

This study developed an integrated ultra-high performance liquid chromatography triple quadrupole linear ion trap tandem mass spectrometry/tandem mass spectrometry (UHPLC-QTRAP-MS/MS) with gas chromatography-mass spectrometry (GC-MS) strategy to quantify 19 constituents of Eupatorii Herba (EH) in rat plasma. The validated method demonstrated acceptable precision (RSD < 13.86%), accuracy (−12.05 to 11.81%), extraction recovery (83.25–116.50%), matrix effect (85.14–115.36%; RSD < 14.10%), and stability (RSD < 13.26%). Key pharmacokinetic findings revealed rapid absorption for all detected analytes, with melilotoside, o-acetyl-p-cresol, and thymol exhibiting the highest systemic exposure. This work provided a validated analytical foundation for further pharmacological research on EH.